An excellent and very educational series. About a newlywed couple who are virgins and their comedic ups and downs in learning how to have sex. Not really a hentai, though there are scenes which can be called hentai. Tastfully rendered taboo themes. A funny "how to" guide for sex illiterate and experts.

On a rainy day, when Mai got stood up by the guy she likes, she met a beautiful girl who told her that she was the Rain and that she had come because of her tears. After that Mai's days were filled with the bitterness of betrayal, only the memory of the girl called Rain can somehow ease her heart. A story of a brief love affair under the rainy season.

A sudden disappearance. And a memo from the lost student's seat. That was only the beginning to the unbelievable events that unfolded.
Original webcomic: http://comic.naver.com/webtoon/list.nhn?titleId=460688&weekday=mon

A story about two young gravure models who have recently made their debut. One of the pair, named Aikawa Miku, is spirited blond that is proud of her gravure status and only all to eager to let any and all know about it. Along with her childhood friend Urushibara Satsuki, she seems intent on making her brother's life as hectic as possible, made all the more simple considering he doubles as the pai...

Kakinozaki Ayana-sensei and student Kagami Yuuki move into a room in the girls dormitory for the new (co-ed) high school semester, requested by Ayana-sensei and approved by the schools' principal. As one would guess, no one can find out he's living there so other than school classes, he has to cross-dress or else he'll be kicked out of school and dorm.

From Kotonoha:
Koume Sato and Kosuke Isobe are two teenagers living in a sleepy seaside town. After getting used and dumped by her crush, the emotionally damaged Koume decides to start a sexual relationship with Kosuke, without any emotions involved. However, they both soon discover that sex with no strings attached do lead to unexpected complications, not just for themselves but also the people ...

Yuuichi a new college student Kissed accidentally Sawako in a party for University student and with?Misunderstanding to another it gave birth to suddenly a MARRIAGE, but the interesting part is the surprising growing relationship between the two classmates! , The latest work of KOTONO Wakako picturing the life of a sweet couple.

From MangaHelpers:
High schooler Shiina Shinya thinks that all girls are pretty much good-for-nothing, mostly because he doesn't understand them at all. That doesn't stop him from being surrounded by strange girls! Tsubasa Tooka, a cute, much-admired girl, stalks him. Shikimura Masami is majorly into masochism, and has recruited Shinya into her play sessions. Ikari Satsuki seems suspiciously in...

Yukino Shiroi is the new cute girl in class, the kind of girl Kyousuke Kai can only dream about. Yet somehow they wind up going out together. It all seems too easy. But the girl has a secret: she draws the most ecchi manga he's ever seen. It's hard to say what will explode first, his heart, his mind, or something else...

Youkadou, a young man working at a certain office is in love with Seiyuu, an extremely beautiful coworker of his. She is in a long distance relationship with her boyfriend, but she agrees to go out with him with one condition: they'll never have sex.

"Progressive Rejuvenation Syndrome." This is an extremely rare disease causing the inflicted person to gradually become younger. The main character of this story, Munenori Agawa, is the only person that could save Rena Amami from this odd disease. Agawa's saliva is the only thing that can halt the disease from making Rena younger, so they must kiss everyday in order for her to survive. T...

Monsters—they're real, and they want to date us! Three years ago, the world learned that harpies, centaurs, catgirls, and all manners of fabulous creatures are not merely fiction; they are flesh and blood—not to mention scale, feather, horn, and fang. Thanks to the "Cultural Exchange Between Species Act," these once-mythical creatures have assimilated into society, or at least, they're t...

Based on the book "Musashi" by Eiji Yoshikawa, Vagabond is an award-winning, fictional retelling of the life of Miyamoto Mushashi, often referred to as the "Sword Saint" - perhaps the most famous and successful of Japan's sword fighters. Shinmen Takezo is destined to become the legendary sword-saint, Shinmen Takezō also known as Miyamoto Musashi, perhaps the most renowned samur...

When the Wischtech threatened to invade the fiefs of Szaalanden, the Emperor dispatched fourteen youths. Of these, the Seven Heroes halted the invasion to herald a time of prosperity while the four Lances of Betrayal were supposedly defeated.
Two decades later, the Lances of Betrayal have reappeared and formed a bandit militia near the frontier fief Gormbark. A man with a black sword and a scar...

From Baka-Updates Manga:
Yuria is a humanoid dutch wife (love doll). A female android designed with the sole purpose of being the sex slave of her master. But she has one flaw. She doesn't want to be a dutch wife. After escaping from her creator, she meets Kubo Shunsuke, who gives her a place to stay. Hilarity is bound to ensue as she battles her programming, which draws her towards him, and pr...